COBATA (X)HTML Constructor is tested and can be used under Wine, which is available for OS X and Linux too. Under Wine the Software's GUI looks like the native OS GUI.
It is possible, additional fonts are necessary to be installed on Wine, in that case just copy them from/ to the \Windows\Fonts directory.
https://steemit.com/cobata/@cobata-bhinkov/updates-of-cobata-x-html-constructor